Shuttleless loom

ABSTRACT

In a shuttleless loom having a reed-carrying frame pivotable about an axis, two opposed needles, one for inserting a weft thread halfway into the shed and the other for picking up the weft thread and drawing it through the second half of the shed; each needle is connected to one end of a flexible ribbon slidable in an arcuate guide which is integral with and substantially in the plane of the reed-carrying frame, and the center of the guide is adjacent the pivot axis of the frame. The other end of the ribbon is connected to a control arm on a shaft which remains perpendicular to the plane of the guide and passes through the center of the latter, and the shaft is oscillated in synchronism with the frame through a rotary shaft of the loom.

United States Patent Juillard 1 July 25, 1972 [54] SHUTTLELESS LOOM [72] Inventor: Yves Julllard, Mulhouse, France [73] Assignee: Societe Alsacienne de Constructions Mecaniques de Mulhouse, Mulhouse, France [22] Filed: Dec. 18, 1969 [21] Appl. No.: 886,298

[30] Foreign Application Priority Date Dec. 24, 1968 France ..68l80332 [52] U.S.Cl. ,.l39/l27R [51] Int. Cl. ..D03d 47/18 [58] FieldofSearch ..l39/l22,l27

[56] References Cited UNITED STATES PATENTS 2,106,727 2/1938 Drobile ..l39/l27 2,657,714 11/1953 Ballber ..139/l23 3,159,186 12/1964 Juillard ..139/127 FOREIGN PATENTS OR APPLICATIONS 7 976,105 10/1950 France ......l39/l23 979,741 12/1950 France ..l39/124A Primary Examiner-Henry S. Jaudon Attorney-Holman & Stern [57] ABSTRACT In a shuttlelessloom having a reed-carrying frame pivotable about an axis, two opposed needles, one for inserting a weft thread halfway into the shed and the other for picking up the weft thread and drawing it through the second half of the shed; each needle is connected to one end of a flexible ribbon slidable in an arcuate guide which is integral with and substantially in the plane of the reed-carrying frame, and the center of the guide is adjacent the pivot axis of the frame. The other end of the ribbon is connected to a control arm on a, shaft which remains perpendicular to the plane of the guide and passes through the center of the latter, and the shaft is oscillated in synchronism with the frame through a rotary shaft of the loom.

2 Claims, 4 Drawing Figures Patented July 25, 1972 4 Shoots-Shoot 2 flrnuns .Zlvvedywg. VVE; JEN-L4: a

Patented July 25, 1972 3,678,968

4 Shuts-Sheet 4.

JIwusuv-at Y; an,

SHUTTLELESS LOOM BACKGROUND OF THE INVENTION This invention relates to shuttleless looms of the type comprising two opposed needles, of which one periodically inserts a weft thread into the shed as far as the halfway position, i.e. into the first half of said shed, while the other needle picks up the thread from the first needle and draws it into the second half of the shed.

The invention relates especially but not exclusively to looms of this type as described in French Pat. No. 1,290,867, i.e. in which the inner end or head of each needle rests freely on the lower sheet of weft threads, close to the reed, while its other end is connected to drive means undergoing an oscillating movement in the axial direction of the needle, so that, under the effect of the weight and inertia of each needle, its head is simultaneously applied against both faces of the dihedral angle formed by the lower sheet of weft threads and by the front face of the reed carried by a frame, so that both needles meet with precision for picking up and passing on the weft thread.

In the above Patent, drive means for each needle has been described, comprising a system of jointed levers. Although such a system is satisfactory for current loom widths, it has a disadvantage in that it is no longer feasible for a wider loom, as the travel imparted to the needles has to be so long that the amplitudes of the pivoting movements of the needle propelling levers lead to oblique positioning of some levers relative to others which, towards the end of the movements, give rise to lateral components which are incompatible with the efficient functioning of the mechanism.

An object of the present invention is to provide a shuttleless loom of the abovementioned type, without the aforesaid disadvantage.

Weaving looms have already been proposed, in which each inserter is fixed to one end of a flexible ribbon whose other end is fixed to an arm which oscillates in synchronism with the frame, But in this type of loom, the shaft carrying the oscillating arm is journalled in the fixed chassis of the loom, so that the ribbons follow fixed paths across the loom, these paths being determined by guides integral with the loom chassis. Such means, therefore, could not be used in looms of the type concerned in the present invention, since the heads of the weft-insertion needles must slide against the front face of the reed which is supported by the frame itself, and is periodicallymoved forwards and backwards. On the other hand, these previously proposed looms, in which each inserter is fixed to the end of a flexible ribbon, although in theory permitting large-width weaving, they do not tolerate the high speeds, for example of 200 strokes per minute, because the ribbon heats up as a result of its successive winding and unwinding in a relatively tight curve of the order of half the height of the loom chassis.

SUMMARY OF THE INVENTION According to the present invention, the drive means for each needle comprises a flexible ribbon sliding in a lateral guide in an arc integral with the reed frame and located substantially in the plane of the latter, the center of said guide [being in the vicinity of the lower pivotal axis of said frame, one end of said ribbon being connected to said needle, and its other end to the end of an arm pivotally mounted on a shaft constantly perpendicular to the plane of the arcuate guide and passing through the center of the latter, said arm-supporting shaft being driven, in operation, with an angular to-and-fro movement synchronous with the movements of said frame, through a transmission which permanently connects it to a rotary shaft of the loom Such a device allows high linear speed of the welt-inserting needles by a very light system of acceptable size.

Moreover, the winding and unwinding of the ribbon takes place in an arc of approximately a quarter of the circumference, and its extent substantially equals the total height of the loom chassis, there being, therefore, much less heating of the ribbon than in looms previously proposed, and so allowing much higher weaving speeds.

Each arcuate guide may comprise an inner wall fixed on the ends of arms radiating from and forming a unit with a supportpiece integral with said frame, and an outer wall fixed to the inner one by U-section yokes lying on their sides, whose two branches are respectively fixed to the outer faces of the said walls, the connection between the ribbon and said arm which moves it being to the side of said guide opposed to that on which are located the closed ends of the yokes.

The invention will be better understood on reading the following description with reference to the accompanying drawings, which show, as a non-limiting example, one embodiment of a large-width shuttleless loom according to the present invention, and in which:

BRIEF DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION OF THE DRAWINGS The shuttleless large-width loom as shown in FIG. 1 has a chassis l with two end-plates 2, 3, a frame or lay 4 with a reed 5 whose two connecting rods 6, 7 are supported by a lower transverse shaft 8 which is journalled in the end-plates 2, 3 of the chassis 1, and a main shaft or crankshaft 12 which also is of the 3 5 journalled in the end-plates 2, 3, and which is connected to the connecting rods 6, 7 by links l3, 14, respectively.

A warp roll or beam is shown at 17, and 18 shows, in the form of a weight suspended from the end of a cord passing over a pulley l9 integral with the rollers 17, a roller-braking device which may be of any suitable type.

Warp threads 25, 26, of which two only are shown for reasons of clarity, unwinding from the roll 17, pass on to a main thread-support 23, an auxiliary thread-support 24, and then split into two sheets, viz: an upper sheet 25 and a lower sheet 26, to form a shed, with the woven fabric passing on to a winder 28, then on to a roller, and finally on to a cylinder on which it is wound in a conventional manner, the roller and the cylinder for winding up the fabric not being visible in the drawings, but being, for example, of the type shown in the abovementioned French Patent. For further details of the structure of these units and their control, reference may be made to that Patent.

For reasons of clarity, the gearing and its control have not been shown. They also are described in the abovementioned French Patent.

The crankshaft 12 is driven, for example, by an electric motor 31 through a belt 32 passing over a pulley 33 of the motor and a pulley-wheel 34 integral with the crankshaft 12.

The positioning of the weft threads in the shed is effected by two needles, i.e. an insertion needle 36 and a drawing needle 37 (see also FIG. 3) fixed, for example, by rivets 39 respectively on the upper ends of two ribbons 38, 38A mounted in the same manner on each side of the loom. The assembly of one only of these will be described, i.e. that of the ribbon 38.

The ribbon 38 slides between two concentric guides 41, 42 (FIGS. 1 and 2), each comprising an arcuate part extended by a rectilinear part ending level with the top of the frame or lay 4. The inner guide 41 is supported in the plane of the frame 4 by arms 46, 47, 48, 49 mounted in and radiating from a support block 52 integral with the frame 4 and pivoting with it on an extension 8A of the transverse lower shaft 8, which is journalled in an auxiliary bearing 54.

The outer guide 42, of which only an upper part has been shown, is kept concentric with the inner guide 41 by yokes 53 whose closed ends are turned for example towards the rear of the loom, so that drive of the ribbon 38 can be effected through the front face of the space between the guides 41, 42. To this end, the lower end of the ribbon 38 is integral withthe end of a pivot arm 56 fixed on a horizontal shaft 57 which can pivot in the support block 52 about an axis perpendicular to the plane of the block 52. The arm 56 is located just in front of the two guides 41 and 42, and it is connected to the ribbon 38 by its bent endas shown at 59.

The shaft 57 is driven with an alternating pivotal movement by the crankshaft 12 through a transmission comprising a cam 61 integral with the adjacent end of the crankshaft l2, aroller 62 co-operating with the cam 61 and carried by a primary lever 63 which can oscillate on the end-plate 2 of the chassis 1 on a horizontal shaft 65, a connecting rod 66, of which one end is connected to the end of the lever 63, another arm 67 pivoting on the block 52 on a shaft 68 parallel to the shaft 57, the end of the arm 67 being connected to the other end of connecting rod 66, a rod 71 (see also FIG. 4) of which one end is connected by a pin 72 to the end of arm 67, and a crank 73 integral with the shaft 57 and whose end is connected to the other end of rod 71. This mechanism allows a pivoting angle of the shaft 57 of the order'of 100 for a pivoting of the lever 67 through an angle of only about 45, with reactions on the shafts which never reach too high values, as could happen if cranks and levers had relative oblique positions too far beyond an angle of 90.

The upper end of rod 66 is fixed to the end of the lever 63 in a slideway 77 in such a way that, in accordance with the position in the slideway in which the said end of the rod 66 is fixed, the length of travel of ribbon 38 can be precisely regulated, for a given cam 61.

A cam 61A fixed on the other end of the crankshaft 12, and for controlling the oscillating movement of the other ribbon 38A is offset by 180 degrees relative to the cam 61, so that the roller 62 co-operating with the cam 61 is on the other side of the axis of the crankshaft relative to the roller which cooperates with the cam 61A. This arrangement ensures a positive connection of the two arms 63, carried by the same shaft 65, whose two activating rollers are thus on each side of cams 61 and 61A which control them respectively. Thus, springs for holding the roller-carrying levers against the cams are unnecessary. An elastic contact is maintained between the rollers and the cams by the fact that the shaft 65, on both ends of which there are mounted the two levers 63, is in the form of a torsion bar. Moreover, one of the two levers 63 is not rigidly fixed directly on theend of shaft 65, but is mounted loose on the latter and connected to it by a stop-screw 75 mounted in a finger 76 integral with the adjacent end of the shaft 65, with the end of the said screw abutting against the face of the lever 63.

Naturally, the invention is not limited to the embodiment described and illustrated; and modifications can be made, depending on the applications envisaged, without, however, going beyond the scope of the invention as defined by the appended claims.

Thus, for example, the system for driving the needles by means of ribbons connected to an oscillating shaft, as described above, may be applied to looms whose needles are not flying as shown in the cited French Patent, but, on the contrary, are kept in guides across the shed.

I claim:

1. In a shuttleless loom having means for shedding warp threads, a ,lay reciprocable longitudinally of the shed formed by said warp threads, weft inserting means including a pair of tape members reciprocable toward and away from each other transversely of the shed, and two mechanisms one at each side of said lay for operating said tape members, each mechanism comprising a support member mounted for reciprocating motion with said lay, a tape restraining structure mounted on said support member and having two mutually facing concentric surfaces defining an arcuate path of substantially 90, a lever having one end connected to the end of the related tape member remote from said shed and having its other end connected to said support member for reciprocating motion about a pivot axis located at the center of said path, and means actuated in timed relationship to the reciprocatory movement of said lay for reciprocating said lever between a position in which said tape member end lies at one end of said path and a position in which said tape member end lies at the other end of said path, a frame, a crank shaft journalled in the frame, said lay being reciprocated through said crank shaft, and said lever reciprocating means comprise a rotatable shaft secured to said other end of the lever and extending through a bore formed in said support member at the center of said arcuate path, a second lever secured to said shaft, a rotatable cam member driven by said crank shaft, a third lever pivotably supported by said frame and having its free end formed with an arcuate slot, a roller carried by said third lever, resilient means acting on said third lever-to maintain said roller in continuous engagement with said cam member, a fourth lever pivotally mounted on said support member so as to have its free end positioned between the free end of said second lever and the free end of said third lever, the length of said fourth lever being greater than that of said second lever, a rod member having one end.

slidably mounted in said arcuate slot of the third lever and its other end articulated to the free end of said fourth lever to transmit the swinging motion of said third lever as caused during the rotation of said cam member to said fourth lever, and a link member articulated at one end to said free end of the fourth lever and articulated at the other end to said free end of the second lever, the length'of said second lever, said third lever, and of said fourth lever being such as to cause reciprocatory rotation of said shaft through an angle of substantialiy 2. The loom according to claim 1, in which said tape restraining structure comprises two parallel arcuate members the inner faces of which constitute said two concentric surfaces, one of said arcuate members being mounted on said support member by means of a plurality of connecting arms converging from the outer face of said one arcuate member to said support member, and the other arcuate member being mounted on said one arcuate member in radially spaced relation by means of a plurality of U-shaped connecting members having one leg secured to the outer face of said one arcuate member and the other leg secured to the outer face of the other arcuate member. 

1. In a shuttleless loom having means for shedding warp threads, a lay reciprocable longitudinally of the shed formed by said warp threads, weft inserting means including a pair of tape members reciprocable toward and away from each other transversely of the shed, and two mechanisms one at each side of said lay for operating said tape members, each mechanism comprising a support member mounted for reciprocating motion with said lay, a tape restraining structure mounted on said support member and having two mutually facing concentric surfaces defining an arcuate path of substantially 90*, a lever having one end connected to the end of the related tape member remote from said shed and having its other end connected to said support member for reciprocating motion about a pivot axis located at the center of said path, and means actuated in timed relationship to the reciprocatory movement of said lay for reciprocating said lever between a position in which said tape member end lies at one end of said path and a position in which said tape member end lies at the other end of said path, a frame, a crank shaft journalled in the frame, said lay being reciprocated through said crank shaft, and said lever reciprocating means comprise a rotatable shaft secured to said other end of the lever and extending through a bore formed in said support member at the center of said arcuate path, a second lever secured to said shaft, a rotatable cam member driven by said crank shaft, a third lever pivotably supported by said frame and having its free end formed with an arcuate slot, a roller carried by said third lever, resilient means acting on said third lever to maintain said roller in continuous engagement with said cam member, a fourth lever pivotally mounted on said support member so as to have its free end positioned between the free end of said second lever and the free end of said third lever, the length of said fourth lever being greater than that of said second lever, a rod member having one end slidably mounted in said arcuate slot of the third lever and its other end articulated to the free end of said fourth lever to transmit the swinging motion of said third lever as caused during the rotation of said cam member to said fourth lever, and a link member articulated at one end to said free end of the fourth lever and articulated at the other end to said free end of the second lever, the length of said second lever, said third lever, and of said fourth lever being such as to cause reciprocatory rotation of said shaft through an angle of substantially 90*.
 2. The loom according to claim 1, in which said tape restraining structure comprises two parallel arcuate members the inner faces of which constitute said two concentric surfaces, one of said arcuate members being mounted on said support member by means of a plurality of connecting arms converging from the outer face of said one arcuate member to said support member, and the other arcuate member being mounted on said one arcuate member in radially spaced relation by means of a plurality of U-shaped connecting members having one leg secured to the outer face of said one arcuate member and the otheR leg secured to the outer face of the other arcuate member. 